CURRENT SITUATION
Dengue viruses are a serious threat to human life as currently
there is no vaccine for Dengue fever. Dengue fever is
caused by one of four closely related virus serotypes
of the genus Flavivirus. Unfortunately the serotypes differ
enough that there is no cross-protection. Dengue cases
in Malaysia increased by 47.5% for the first eight months
of this year compared to the same period last year.
More than 30,000 cases and 74 deaths have been
reported during the period.* Rapid identification
and early detection of the Dengue serotype
responsible for an outbreak remains difficult. Current diagnostics methods based on the isolation and culture of virus or serological testing are time consuming and ill-suited for large-scale healthcare initiatives. A system for rapid, low-cost, accurate diagnosis of Dengue infection would enable treatment and care to be rapidly administered to the correct patients at an earlier time-point in disease progression. This would maximise the chances of recovery as well as minimise expending resources on false positives.
SOLUTION
Development of a Dengue virus-specific microarray chip. This chip is spotted with probes of various known Dengue viruses with signature sequences for each serotype.
BENEFIT
This method offers faster and more accurate diagnosis. Results can be attained within a few hours as compared to two to three days using conventional approaches. SynaProbe™ can be used to design Dengue virus-specific probes for each serotype. Tests against human and viral genomes can be carried out using SynaHybridise™ to ensure specificity of the probes.
WHAT ARE SynaProbe AND SynaHybridise?
SynaProbe is used to design probes for genes or mRNA transcripts. SynaProbe has been developed to meet the requirements for rapid design of oligomer probes used for microarrays. It enables users to find the best probe sequence by weighting parameters according to user defined input settings. SynaHybridise is designed to rapidly search short reads against a large dataset to characterise the specificity of microarray probes. It is also used to determine potential false positives due to non-specific hybridisation.
To run the example above, please follow the instructions below:
  1. Go to www.mgrc.com.my.
  2. Click on SynaProbe.
  3. Click on the Test Sequence and select 'Dengue Virus Type-2'.
  4. Click PROBE button.
  5. On the results page, select Probe 1 and click the button.
  6. Click on HYBRIDISE button.
Figure 1: The result shows the top 10 probes. Click the button highlighted in red to test the selected probe (probe 1) for specificity with SynaHybridise.
Figure 2: The result from SynaHybridise shows that the probe is specific to Dengue Virus Type-2.
* The Star, November 7, 2007

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